Resilient bridge for stringed musical instruments



March 23, 1937. v. D1 MARZIO RESILIENT BRIDGE FOR STRINGED MUSICALINSTRUMENTS Filed April 23, 1956 .m m .U Wm ...M nBwH l ff-L ngi.'

Patented Mar. 23, 1937 RESILIENT BRIDGE FOR STRINGED MUSICAL INSTRUMENTSVincent Di Marzio, Swissvale, Pa.

Application April 23,

Claims.

My invention relates to resilient bridges for stringed musicalinstruments, and particularly to resilient bridges for instruments whichare played by picking or plucking the strings, such for example, asguitars, mandolins, and the like, although it is also useful on otherstringed instruments of this general class or type.

One object of my invention is to increase the life of the strings of theinstrument on which it is used.

Another object of my invention is to improve the tone quality of theinstrument on which it is used.

A further object of my invention is to enable the 'i5 player of aninstrument on which it is used to ob- 'tain vibrato or tremolo tonesmore readily than has heretofore been possible.

I will describe three forms of bridges embodying my invention, and willthen point out the novel features thereof in claims.

In the accompanying drawing, Fig. l is a top plan View showing a guitarprovided with a bridge embodying my invention. Fig. 2 is a top plan Viewshowing, on an enlarged scale, the bridge removed from the instrument.Fig. 3 is a front view, partly in elevation and partly in section, ofthe bridge shown in Fig. 2. Fig. 4 is an end View of the bridge shown inFigs. 2 and 3. Fig. 5 is a sectional view taken on the line V-V of Fig.2. Fig. 6 is a view similar tol lfFig. 2 showing a modified form ofbridge also embodying my invention. Fig. '7 is another view similar toFig. 2 showing another form of bridge embodying my invention.

Similar reference characters refer to similar parts in each of theseveral views.

Referring first to Fig. 1, I have here shown one form of bridgeembodying my invention applied to a guitar A having the usual body I,neck 40 2, tail piece 3, and strings 4. The bridge, which bridge isdesignated as a whole by the reference character B, comprises a basemember 6 which rests on the top of the instrument, and a top bar I whichis resiliently supported on the base member 6 by suitable means, hereshown as a pair of coil springs 8. The coil springs are held in theproper positions between the base member 6 and the top bar 'I by meansof posts 9 which project upwardly from the base member through thesprings and through clearance holes I0 provided in adjusting nuts IIwhich are screwed into tapped holes I2 formed in the top bar 1. The topbar is provided with holes I3 through which the strings 4 pass, and itwill be obvious that by screwing the adjusting nuts 1936, Serial No.75,960

(Cl. 84-307) f II into or out of the tapped holes I2, the top bar 'l maybe lowered or raised, thus enabling the elevation of the strings abovethe fingerboard to be adjusted to meet the requirements of theparticular instrument, or the desires of the player. To facilitateadjustment of the adjusting nuts, these nuts are provided with knurledflanges IIa, which flanges also serve to provide a good bearing surfacefor the upper ends of the springs 8. The central portion of the top barl, that is to say that portion in which the holes I3 for the receptionof the strings 4 are provided, is preferably made triangular in shape,

as shown in Fig. 5, and the lower portions of the holes I3 are roundedin the manner shown, to decrease wear on the strings. The base member 6and top bar 'l may be made of any suitable materials, the preferredmaterial being hard wood, such for example, as ebony.

With the bridge constructed in the manner described, it will be apparentthat the bridge is held in place on the instrument by the componentforces of the strings 4 in tension, which component forces compress thesprings 8 to a point where a balance is reached. It will also beapparent that any sudden stresses which are produced in the strings whenthe instrument is being played will be cushioned by the springs, and thelife of the strings is therefore greatly lengthened. Furthermore, I havefound that by properly designing the parts, and particularly the springs8, it is possible to obtain from inferior instruments tones having aquality which can generally be obtained only from the better grades ofinstruments. I have also found that by resting the palm of the handwhich is used to pick the strings on the top of the top bar l, andmoving the hand in a manner to vibrate the top bar, it is possible toreadily obtain a vibrato or tremolo tone, which tone is extremelydifficult to obtain on instruments which are provided With the usualsolid type of bridge.

Referring now to Fig. 6, in the modied form of bridge here shown thesprings 8 which resiliently support the top bar 'l are enclosed withintubular members I4 which are secured at their lower ends to the basemember 6, and which slidably cooperate at their upper ends with cupshaped guides IIb formed integrally with the flanged portions Ila of thenuts Il. It will be obvious that when the bridge is constructed in themanner shown in Fig. 6, it will function in the same manner as when itis constructed in the manner illustrated in the preceding views,

but the appearance of the bridge is improved due to the fact that thesprings are wholly hidden from View.

Referring now to Fig. 7, in the modified form of bridge here shown, theresilient means for supporting the top bar 'l comprises a leaf spring I5provided at its ends with U-shaped return bends E53 and l5b. The lowerportion of the leaf spring is secured to the base member 6 within agroove E@ which is provided in the upper side of the base member, whilethe confronting ends of the return bends are secured to the underside ofthe top bar. The construction shown in Fig. 7 is cheaper than that shownin the preceding views, but is subject to the disadvantage that theheight of the top bar with respect to the base member 6 is notadjustable.

It should be particularly pointed out that while it is preferable in allforms of my invention to. use a top bar having holes through which thestrings pass rather than grooves for the reception of the stringsbecause of the fact that it is. contemplated to vibrate the top bar byplacing the hand on it, the top bar may, if desired, be provided withnotches in its upper surface in place of the holes I3 for the receptionof the strings.

Although I have herein shown and described only three forms of resilientbridges embodying my invention, it is understood that various changesand modifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. In a bridge for stringed musical instruments, the combination of abase member, upwardly projecting posts secured to said base memberadjacent its ends, coil springs surrounding said posts, a top barprovided with screw threaded holes through which the upper ends of saidposts pass with clearance, and adjusting nuts screwed into said holesand resting on the upper ends of said springs and provided with holeswhich slidably receive the upper ends of said posts, whereby said topbar is resiliently supported in an adjustable position by means of saidsprings.

2. In a bridge for stringed musical instruments, the combination of abase member, a top bar supported on said base member by means of springsand provided with means for the reception of the strings, and adjustablemeans for varying the elevation of said top bar relative to said basemember.

3. In a bridge for stringed musical instruments, the combination of abase member which is adapted to rest on the top of the instrument, a topbar mounted for sliding movement relative to said base member andprovided with through holes for the reception of the strings, and springmeans interposed between said base member and said top bar for urgingsaid top bar to a spaced position relative to said base member.

4. In a bridge for stringed musical instruments, the combination of abase member adapted to be mounted on the top of the instrument and a topbar resiliently supported on said base member by means of springs, saidtop bar being provided with a central triangular portion having its basedisposed at the top of the bar and having holes extending therethroughnear the apex thereof, said holes being formed with rounded lowerportions to decrease string wear.

5. In a bridge for stringed musical instruments, the 'combination of abase member, an upwardly extending tubular member secured to said basemember adjacent each end of said base member, a coil spring disposed ineach tubular member, a top bar disposed in alignment with said basemember and provided adjacent each end with a screw threaded hole whichaligns axially with one of said tubular members, and an adjusting nutscrewed into each screw threaded hole and resting at its lower end onthe upper end of the adjacent spring and provided with a cup shapedguide which slidably receives the upper end of the adjacent tubularmember, whereby said top bar is resiliently supported in an adjustableposition by means of said springs.

VINCENT DI MARZIO.

